Phoenix police gather near Mother of Mercy Mission Catholic Church where a priest was shot to death and another badly injured Wednesday night. (Source: CBS 5 News)

Three women pray the Rosary at Mother of Mercy Mission Catholic Church in Phoenix after a priest was found dead and another badly injured. (Source: CBS 5 News)

The woman comfort each other as the grief grows over news of the priest's killing. (Source: CBS 5 News)

PHOENIX (CBS5) -

The Rev. Kenneth Walker was a simple man, but one who served his Catholic parish in downtown Phoenix faithfully in the two years since he was ordained.

But his service to the congregations of Mother of Mercy Mission Catholic Church was cut short when he was gunned down in the church during an attack that also left another priest hospitalized in serious but stable condition.

Police said Walker, 28, and the Rev. Joseph Terra, were victims of what was initially reported as an attempted robbery at the Mother of Mercy Mission Catholic Church at 16th Avenue and Monroe.

Police said Terra was able to call 911 shortly after 9 p.m. The 56-year-old was in extremely critical condition with unknown injuries, said Phoenix police Sgt. Steve Martos.

Police chief Daniel Garcia said investigators have strong physical evidence but that they lack eyewitness information and had no suspects in custody.

"We need the community to step forward," Garcia said during a news conference Thursday morning at police headquarters in which he termed the crimes "very tragic and appalling."

Garcia said few other details would be released because it was so early in the investigation, but that Phoenix police will "exhaust resources" to bring to justice the individual or individuals involved.

Phoenix Mayor Greg Stanton assured officials of the church and the Catholic Diocese of Phoenix that the "entire city stands with you."

Stanton said Walker's killing and the attack on Terra "strikes at our core."

"Every American should feel safe in a house of worship," Stanton said. "That basic value was violated last night in an unspeakable way."

Martos said investigators were able to briefly interview Terra, who had been physically assaulted, on Wednesday night, but that he provided limited information, though he was able to call police and report the crime, Martos said.

"Hopefully, once (Terra) receives treatment and is able to pull through, we can gather more information," Martos said.

Walker, of Maple Hill, KS, was ordained just two years ago and was taken to a Phoenix hospital where he died, said the Rev. Fred Adamson of the Catholic Diocese of Phoenix.

Adamson said he was not aware of any type of security at the church and that Terra was a strong man who not afraid of anyone, but "would give you the shirt off his back."

He said it was his understanding that Terra was able to absolve and issue last rites for Walker.

Adamonson, who was representing the diocese in the absence of Bishop James Olmsted, who was out of town, said the priests had lived there the past four years.

Martos said the crimes occurred inside the church's rectory.

Parishioners outside the church prayed the rosary with their hands clasped and heads bowed early Thursday morning. One woman said Walker had recently baptized her baby.

Police found a 2003 Mazda Tribute believed stolen from the church about four blocks north of the scene. They towed it to begin processing it for fingerprints and any other evidence.

No suspects were in custody, Martos said, but "it's just a matter of time that we can locate these individuals."

The church is in an area near the state Capitol and other government buildings that might have surveillance cameras, and Martos said police were contacting Capitol Police and looking into whether any of the cameras might have filmed the suspects Wednesday night.

"It says a lot when talking about individuals who are coming into a location like this to a church facility and commit a crime like this against individuals like this," Martos said. "One can only imagine what they are likely to do."

The Catholic Diocese of Phoenix issued the following statement Thursday morning on Twitter:

We are stunned and deeply saddened to learn of the tragic assault perpetrated last night against Fr. Joseph Terra and Fr. Kenneth Walker, two religious order priests who belong to the Priestly Fraternity of St. Peter. Fr. Walker's life was taken. Fr. Terra remains in critical condition but stable. The reported attack occurred at Mater Misericordiae Mission in Phoenix. The police are still gathering information and trying to sort through the details of this senseless act of violence. We ask that people offer prayers for both priests, the religious community, their families and the parish. Eternal rest, grant unto him O Lord and let perpetual light shine upon him. May he rest in peace.

A 6:30 a.m. Mass scheduled at the church was moved to 7 a.m. at St. Catherine's Catholic Church at Central and Southern Avenues in Phoenix.

Anyone with information about the suspects or incident are asked to call Silent Witness at 480-WITNESS (480-948-6377), or 480-TESTIGO (480-837-8446).

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